/*
 * Created on 13-May-2005
 * Created by Paul Gardner
 * Copyright (C) Azureus Software, Inc, All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 */

package com.aelitis.azureus.core.util.bloom.impl;

import java.util.Arrays;
import java.util.Map;

import com.aelitis.azureus.core.util.bloom.BloomFilter;

public class BloomFilterAddRemove8Bit extends BloomFilterImpl {
    private byte[] map;

    public BloomFilterAddRemove8Bit(int _max_entries) {
        super(_max_entries);

        map = new byte[getMaxEntries()];
    }

    public BloomFilterAddRemove8Bit(Map<String, Object> x) {
        super(x);

        map = (byte[]) x.get("map");
    }

    protected void serialiseToMap(Map<String, Object> x) {
        super.serialiseToMap(x);

        x.put("map", map.clone());
    }

    public BloomFilter getReplica() {
        return (new BloomFilterAddRemove8Bit(getMaxEntries()));
    }

    protected int trimValue(int value) {
        if (value < 0) {
            return (0);
        } else if (value > 255) {
            return (255);
        } else {
            return (value);
        }
    }

    protected int getValue(int index) {
        return (map[index] & 0xff);
    }

    protected int incValue(int index) {
        int original_value = getValue(index);

        if (original_value >= 255) {

            return (255);
        }

        setValue(index, (byte) (original_value + 1));

        return (original_value);
    }

    protected int decValue(int index) {
        int original_value = getValue(index);

        if (original_value <= 0) {

            return (0);
        }

        setValue(index, (byte) (original_value - 1));

        return (original_value);
    }

    private void setValue(int index, byte value) {
        map[index] = value;
    }

    public void clear() {
        Arrays.fill(map, (byte) 0);

        super.clear();
    }
}
